Most of the dosimetry work that is carried out at REB has direct or indirect applications to the assessment of radiation doses from bioterrorism events involving environmental radiation. Accurate assessment of doses permits accurate projections of long-term cancer risks to be made. Since 2005, all of the bioterrorism-related studies at REB are funded under an Inter-Agency Agreement between NIAID and NCI. Examples of completed and continuing REB activities relevant of bioterrorism follow.<ul style="font-size: 8pt; font-family: Verdana"> <li><b>Radioactive Fallout from Nuclear Weapons Tests:</b> With regard to the studies of radioactive fallout from nuclear weapons test, the completed studies include: (1) The preparation of a web-based calculator for estimating individual thyroid radiation dose from I-131 originating from Nevada Test Site fallout and the related thyroid cancer risk, and (2) The preparation of a report of a Congressionally-mandated feasibility study on radiation doses received by the American people from fallout from all nuclear weapons tests worldwide. The continuing studies are: (1) The development of a joint methodology for assessment of radiation doses from nuclear tests conducted at Semipalatinsk, (2) Conduct of an epidemiologic study on thyroid cancer and thyroid disease risks following exposure to environmental radiation active fallout from the Semipalatinsk (Kazakhstan) nuclear test site, (3) The acquisition of data on residential history, foodstuff consumption rates, and agricultural practices to be used in the joint methodology and in the Kazakhstan epidemiologic study, (4) As mandated by Congress, the assessment of doses and risks from nuclear tests conducted in the Marshall Islands, and (5) Archiving historical fallout data and national and international reports on fallout and developing an electronic database on fallout measurements worldwide.</li><br><br><li><b>Evaluation of Consequences of Radiation Accidents:</b> With respect to the evaluation of the consequences of actual or hypothetical radiation accidents, a study was completed in which a database was developed of stable chromosome aberration rates for unexposed people of all ages. The data could be used following exposures from a nuclear terrorist event or accident to distinguish between unexposed persons from those with moderate exposure. Continuing or new studies include: (1) The estimation of radiation doses by people exposed to emissions from the Chernobyl accident, (2) The rapid assessment of individual doses from external irradiation following a nuclear event; and (3) The evaluation of the organization, implementation, and efficacy of the countermeasures used after the Chernobyl accident.</li><br><br><li><b>Development of New Methods:</b> Regarding the development of new methods, several innovative studies are underway and continuing, including (1) The development of improved biodosimetry techniques using human tooth enamel and optically-stimulated luminescence (OSL) and electron paramagnetic resonance (EPR), (2) Corroboration of analytical dosimetry estimates via biodosimetry measurements, (3) The assessment of doses per unit intake of I-131 for healthy people and for people suffering from thyroid diseases, and (4) A literature review and some planned experiments to quantitatively estimate the transfer of certain radionuclides (those considered as likely to be used in dirty bombs) to animal milk and dairy products.</li><br><br><li><b>Training and Communication:</b> A number of studies or activities are also devoted to training and communication. Completed activities include: (1) The organization of special sessions on radiation dosimetry at the 2004 annual meeting of the Health Physics Society and at the BioDosEPR Symposium in July 2006, and (2) The preparation of a special issue of Radiation Research describing how dosimetry methods are applied in the assessment of medical, occupational, and environmental radiation doses. Continuing activities include participation in programs and expert committees of national and international organizations, e.g., National Council on Radiation Protection and Measurements (NCRP), the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA), and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). In addition, training in radiation sciences for personnel who could be involved in the mitigation of nuclear events is provided including a one-week course on Radiation Epidemiology.</li></ul